Craniofacial surgery can be used to correct a number of conditions of the jaw and face related to structure, growth, sleep apnea, correcting malocclusion problems owing to skeletal disharmonies or other orthodontic problems that cannot be easily treated with braces. During craniofacial surgery an osteotomy is often performed in which the bones can be cut, realigned, and held in place with either screws or plates and screws.
Distraction devices (commonly referred to as distractors), are used to gradually adjust the relative orientation and spacing of bone parts on opposing sides of an osteotomy. Distractors typically consist of transcutaneous pins or screws secured to the bone on either side of the osteotomy together with a mechanism that allows controlled incremental adjustment of the distance between parts of the distractor on opposing sides of the osteotomy and the bone segments the parts of the distractor are attached to. Typically, distractors are used to perform distraction osteogenesis (the formation of bone).
Some surgical procedures may include a series of adjustments to the bone segments that have been separated by the osteotomy. These adjustments may be spaced out over a relatively significant amount of time, for example a number of weeks or months. In some cases the patient of the surgical procedure may be instructed to perform a series of adjustments to the distractor to adjust the distance between the bone segments. For example the patient may be instructed to adjust the distractor to increase the distance between the bone segments by 1 mm (millimeter) once every day.
A typical distractor is adjustable such that the distance between the attached bone segments can be increased, for example by actuating the distractor in a first direction, and decreased, for example by actuating the distractor in a second direction. If the series of adjustments the patient is to perform are all in a single direction, for example, increasing the distance between the bone segments, a bone distraction system that prevents the patient from actuating the distractor in the incorrect direction may improve the results of the surgical procedure.
During the surgical procedure, the surgeon may wish to make adjustments to the distance between the bone segments in both directions, for example increasing and decreasing the distance. Thus, a bone distraction system that also allows the surgeon to actuate the distractor in both directions may improve the results of the surgical procedure.